Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Wireless power transfer is a technology that can wirelessly transfer power to a device using coils. This technology can be used, for example, to charge the battery of a device using a signal that is delivered to the device wirelessly. Generally, power is wirelessly delivered when a source's transmit coil couples with a device's receive coil.
Although many devices may benefit from wireless power transfer, there are many factors that complicate the effective delivery of power wirelessly. For example, the size of the device, the shapes of the transmit coil and of the receive coil, and the distance between the transmit coil and the receive coil are examples of such factors. In addition, many of these devices are portable. The portability of the devices results in changes in positional relationships that further complicate the wireless delivery of power. In addition, the ability to effectively deliver power to multiple devices also impacts wireless power deliver.